A novel method for Eosin Y-catalyzed photooxidation of triarylphosphines under visible light irradiation and aerobic conditions was reported.

Magnetic nanoparticles, such as Fe₃O₄ and Co₃O₄, play a vital role in the research on advanced microwave absorbing materials, even if problems such as high density and narrow band impedance matching are still unsolved. Herein, the study of lightweight hollow Fe₃O₄@reduced graphite oxide (RGO) nanocomposites synthesized via the solvothermal method is presented. The microstructure and crystal morphology of the materials were characterized by X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses. Single crystalline hollow Fe₃O₄ spheres were grown onto RGO flakes, leading to the formation of heterojunction, which further influenced the microwave absorption properties. The latter were evaluated by standard microwave characterization in the frequency range of 2–18 GHz. It was found that, for a specific Fe₃O₄@0.125 g RGO composite, the minimum reflection loss can reach −41.89 dB at 6.7 GHz, while the reflection loss was less than −10 dB from 3.4 GHz to 13.6 GHz for a nanocomposite sample thickness in the range of 1–4 mm. The combination of these two materials thus proved to give remarkable microwave absorption properties, owing to enhanced magnetic losses and favorable impedance matching conditions.

Two well-defined double hydrophilic graft copolymers comprising a hydrophilic poly(2-hydroxyethyl acrylate) (PHEA) backbone and hydrophilic poly(N-isopropylacrylamide) (PNIPAM) side chains were synthesized by the combination of reversible addition–fragmentation chain transfer (RAFT) polymerization, single-electron-transfer living radical polymerization (SET-LRP), and a grafting-from strategy. A 2-hydroxyethyl 2-((2-chloropropanoyloxy)methyl)acrylate monomer containing an SET-LRP initiating group (–OCOCH(CH₃)Cl) was first RAFT homopolymerized to provide a PHEA-based homopolymer bearing a Cl-containing SET-LRP initiating group in every repeated unit with a narrow molecular weight distribution (M_w/M_n = 1.17). This homopolymer directly initiated SET-LRP of N-isopropylacrylamide at ambient temperature to afford the desired well-defined poly(2-hydroxyethyl acrylate)-graft-poly(N-isopropylacrylamide) graft copolymers (M_w/M_n ≤ 1.33) with hydroxyl in every repeated unit of the backbone without polymeric functionality transformation. The thermo-responsive phase behavior of the obtained double hydrophilic graft copolymers was investigated by UV/vis spectroscopy, ¹H NMR, and dynamic light scattering (DLS).

In this study, hollow cube-like CuS composites derived from Cu₂O crystals were synthesized via a simple one-step reaction. The formation of hollow cavities can be explained through the Kirkendall-based process. The morphologies and electromagnetic absorption (EA) properties of the CuS were measured and investigated. A sample with 35 wt% hollow CuS loading paraffin-composite achieves an optimal reflection loss (RL) of −63.99 dB at 12.09 GHz under the thickness of 2.25 mm. Simultaneously, the effective EA bandwidth (RL ≤ −10 dB) can be tuned between 4.63 and 18.00 GHz by changing the thickness of the absorber from 1.5 mm to 4.0 mm. The excellent EA performance is attributed to the high dielectric loss, appropriate impedance matching and multiple reflections induced by the unique hollow cube-like structure. Thus the hollow cube-like CuS is expected to be a promising material in approaching for microwave absorption against the electromagnetic pollution.